Sign-in to Ask A Doctor - 24x7
OR
Sign in with Google
Is RPR Test Done 5 Months Post Exposure Conclusive?
Question: I am worried about RPR false negatives. I engaged in high risk sex and tested for syphillis using the RPR test on the 43rd day, again at about 5 and half months and one last time at 16 and half months. RPR was negative each time. However I recently read that the test is inaccurate under these situations:
1. Early and latent stage
2. Prozone phenomenon
Q1. As my health check included HIV MEIA tests at the same dates as above, I am assuming the latter can be ruled out. We can also say that the first and third tests could be false negatives. However how reliable is the test done at 5 and half months ?
Q2. It has been 6 and half years since then. What test can I use now ?TPHA ?
1. Early and latent stage
2. Prozone phenomenon
Q1. As my health check included HIV MEIA tests at the same dates as above, I am assuming the latter can be ruled out. We can also say that the first and third tests could be false negatives. However how reliable is the test done at 5 and half months ?
Q2. It has been 6 and half years since then. What test can I use now ?TPHA ?
Brief Answer:
Can go for Tpha for confirmation
Detailed Answer:
Hello. Thank you for writing to us
I am dr.kakkar(dermatologist and venereologist). I have gone through your query and I have noted your concern.
Incubation period of syphilis varies from 9 - 90 days. However most will have serologic evidence within 4 weeks of infection. Moreover vdrl/rpr becomes reactive within a week after the appearance of syphilitic chancre. However I assume that you did not had a chancre at all. Therefore your tests at 43 days is fairly reliable. At 5 months it is very reliable.
It is common practice to do a specific serologic test e.g tpha along with a screening vdrl/rpr for a more reliable diagnosis specially in the presence of a clinical features and if one suspects prozone phenonmena or latent syphilis.
You can certainly go for tpha for your satisfaction and that result would be conclusive.
Regards
Can go for Tpha for confirmation
Detailed Answer:
Hello. Thank you for writing to us
I am dr.kakkar(dermatologist and venereologist). I have gone through your query and I have noted your concern.
Incubation period of syphilis varies from 9 - 90 days. However most will have serologic evidence within 4 weeks of infection. Moreover vdrl/rpr becomes reactive within a week after the appearance of syphilitic chancre. However I assume that you did not had a chancre at all. Therefore your tests at 43 days is fairly reliable. At 5 months it is very reliable.
It is common practice to do a specific serologic test e.g tpha along with a screening vdrl/rpr for a more reliable diagnosis specially in the presence of a clinical features and if one suspects prozone phenonmena or latent syphilis.
You can certainly go for tpha for your satisfaction and that result would be conclusive.
Regards
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Dr Kakar,
Sorry have to give the full context:
In an act of escape from an engagement I never wanted I engaged in 2 acts of high risk sex with sex workers , separated by 15 days. I used a condom, and thus never thought about Syphillis as a risk then. On the 4th day following the second incident ( thus 19 days from incident 1 and 4 days from 2) , I noticed a 2-3 mm circular sensitive patch on my scrotum, which to me looked like Vitamin deficiency mouth ulcers look. I was not sure if my application of dettol directly on the skin caused it or something else. But it was sensitive to touch ( burning) when coming in contact with skin. It healed after two days. I do not know if this is a chancre or not . I did not know then that while 99% chancre's occur on the penis, 1% could be elsewhere. Also, the rapid healing, the presence of burning on touch did not seem typical of syphilis.
I was worried about it being herpes but tested negative then and repeated it this year, still negative. So I do not know what that was.
Sorry have to give the full context:
In an act of escape from an engagement I never wanted I engaged in 2 acts of high risk sex with sex workers , separated by 15 days. I used a condom, and thus never thought about Syphillis as a risk then. On the 4th day following the second incident ( thus 19 days from incident 1 and 4 days from 2) , I noticed a 2-3 mm circular sensitive patch on my scrotum, which to me looked like Vitamin deficiency mouth ulcers look. I was not sure if my application of dettol directly on the skin caused it or something else. But it was sensitive to touch ( burning) when coming in contact with skin. It healed after two days. I do not know if this is a chancre or not . I did not know then that while 99% chancre's occur on the penis, 1% could be elsewhere. Also, the rapid healing, the presence of burning on touch did not seem typical of syphilis.
I was worried about it being herpes but tested negative then and repeated it this year, still negative. So I do not know what that was.
Brief Answer:
Does'nt seem like an STD
Detailed Answer:
Hi.
It could have been a bacterial skin infection or an ingrown hair or due to trauma from shaving.
Good that you ruled out Genital Herpes. This would have been my possibility had'nt you already ruled out.
You can take a TPHA test and put matters to rest although fast resolution makes it unlikely that it was a chancre.
Regards
Does'nt seem like an STD
Detailed Answer:
Hi.
It could have been a bacterial skin infection or an ingrown hair or due to trauma from shaving.
Good that you ruled out Genital Herpes. This would have been my possibility had'nt you already ruled out.
You can take a TPHA test and put matters to rest although fast resolution makes it unlikely that it was a chancre.
Regards
Note: Consult a Sexual Diseases Specialist online for further follow up- Click here.
Above answer was peer-reviewed by :
Dr. Chakravarthy Mazumdar
Answered by
Get personalised answers from verified doctor in minutes across 80+ specialties
